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Subsonic-Supersonic Supersonic-?

  1. Sep 10, 2006 #1
    Subsonic-Supersonic... Supersonic--?

    Hi all,

    I was just wondering.. in the case of the Laval nozzle you go from subsonic to supersonic. But once your flow is already supersonic is there any sense in having a physical nozzle (as surely there is still some divergence to the exhaust) or would it just impede flow? I am thinking about use above the atmosphere.


  2. jcsd
  3. Sep 10, 2006 #2


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    Staff: Mentor

    The flow continues to expand and accelerate, guided by the nozzle. There is an optimal nozzle length, though, and some nozzles are actually extendable: http://www.braeunig.us/space/sup1.htm
    Last edited: Sep 10, 2006
  4. Sep 10, 2006 #3
    Thanks, thats a great website.

    I now see you need different nozzles for different missions depending on the altitude.
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